Shock absorber



Patented ug. 30, 1927.

UNITED STA FRANK J'. LAHER, 0F PORTLAND, OREGON.

TES PATENT OFFICE.

SHOCK ABSORBER.

Application filed May 21, 1925. Serial No. 31,820.

road surface. Said devices are arranged to check the rebound produced by the vreturn ilexure of said springs rather than to modify the flexure itself.

lieretofore, the devices of the strap-and? drum type, of which this is a modification, have been characteristic by the provisionnof means which utilize friction, for thermajor f part, in checking rebound, Friction produces severe wear and also often times produces squeeks and chatter unless lubricated and if lubricatedtlie degree of lubrication affects the gripping force of the friction surfaces.

The object offvcmy invention is to provide a device vof this character with checking devices which comprise a revoluble drum element, the rotation of which, in the major part, is controlled bya spring element which is flexed or compressed oppositely to the load carrying spring, said two spring elements be ing connected by a flexible member.

A further object of my invention is to provide means for varying the degree of resistance of recoil of the vehicle springs inversely as the recoil movement progresses, the resistance force, however, remaining practically uniform.. By arranging the devices in this manner a relatively large flexure or compression of the vehicle springs will be snubbed more severely than will a lesser distortion and thus the checking will be proportioned to the distortion, that is, the resistance of the coil spring will be increased in proportion to the probable recoil thereof.

I attain this object by providing a revoluble spring-controlled drum preferably provided witli cable grooves arranged spirally relatively to the axis of rotation of said drum, the courses of said spirally wound cable thereon being arranged a progressively decreasing distance from the axis of rotation 0f said drum. Hence, the cable thus wound and connecting the body of the vehicle to the axle will exert a varying effective force against vthe load-carrying springs of the vehicle, said force increasing with the degree of iiexure or compression of said springs.

A further object of my invention is to provide a device of this character with bearing members for the drum which are adapted to interpose a substantial resistance to the rotation thereof, said bearing members being adjustable to vary said resistance. The

iiiterposition of a minor amount'ofV resist- Y ance to rotation tends to prevent the druml from being spun about its axis at a greater rate than the cable or other flexible ooniiection is unwound therefrom. saiddrum might cause the cable or other iiexible connection to be thrown froml the guiding means provided therefor on said drum. v

Lilie details of construction and mode of operation of my device ai'e hereinafter described with reference to the accompanying drawings, in which:

lfig'. l is an elevation Of my device with a portion of the housing being shown as broken away to disclose the spiral winding of said cable about the drum, the drum being shown as rotated as when the load-carrying spring is flattened to the maximum degree;

ltig. 2 is a section taken on the line 2-2 of Figpl, and shows the spiral arrangement of the cable way and the similar windingL about the drum;

llig. 3 is a transverse section taken on the line of Fig. l, showing the drum as r0- tatably mounted ,and the adjustable devices by which the resistance of the rotation of said drum may be adjusted; and

Fig. e is a section taken on the line l-t of Fig. 3, disclosing the arrangement of the retraction spring which acts against the return ilexure of the load-carrying springs. v

My device is preferably adapted to be car ried upon one of the frame sides a of a ve-A hicle and comprises a. base i), a drum c rotatably carried by a trunuion b which is preferably integral with said base, and a housing Z which is adapted to enclose both said base opinning of and said drum, said covei being fastened to l said base by screws oi studs e, shown in Filo'.

o. Said base is preferably fastened tosaid frame by bolts f5' said bolts preferably being counter-sunk, as shown in Fig. 3, so that the tops of their heads lie flushwith the inner Y surface of said base,

The drum is preferably provided with a l Over said guideway the connecting cable rso g is mounted, said cable being fastened to the drum by a clamp L and being fastened at its opposite end to the transverse axle z' of the vehicle. Said frame side a is spaced from the axle z by any type of supporting spring (not shown herein, or formingany part of this invention), said spring being compressed by the weight of the vehicle when the wheels, carried by the axle i, fall into a rut, or the like.

I provide a spirally wound spring j within the hollow drinn c, one end .7" of which is fastened to said drum by bolts or screws hand the other end of which is fastened to the base b, by a pin Z. Said cable g is fas tened to said axle in such a manner that the spring y' is maintained at a flexed or com- `pressed position and thus the cable is maintained taut between the point at which it leaves t-he drum, and the axle. As the spacing between 'the axle 71 and the frame side a increases the distance between the drum and Ithe'v axle correspondingly increases so as 'to cause thedrinn to be rotated against "the action ofthe coil spring y and to cause said cable to leave said drum at different points kupon its cable way dueto the rotation of said drum. The increase in yspacing between said yaxle and vsaid frame side and the 'resultant rotation of the drum causes the point atzwh-ich-the'cable lea'ves'tlie drumto be progressively increased, due tothe spiralar-v side.

tion, this material preferably being leather or other material commonly provided for braking surface. Such material preferably is slightly flexible and `compressible and I provide tapered adjusting members a which are arranged between said bearing member said drum.

and thehub c2 of said drum so that theresistance to the rotation of saiddrum can be adjusted. I provide a plate o upon the outer `face of saiddrum which overlies said tapered members and provide a screw Z2 whichfis ,threaded into said trunnion b. The setting down of said screw tends to move 4saidfpl'ate -o inwardly therewith and to force the tapered member n further into saidhub and to force the bearingl member more `tightly Vagainst the trunnionato lincrease the yresistance to the turning of said drum. rihe head of said screw preferably extendsthrouglrthe housing lso that it can be adjusted without removing lsaid housing.y

I' claim:

l. In a shock absorberof the character describedfabase, a rotatable drum mounted thereon, a spiral springoontrolling =the rotation thereof, a. flexible lconnection/member wound about the peripliery-of said drumin a. directionopposite -to y*that -in which said spring tends to rotate said-drum, the` mounting for said drum onfsaidbase having a face of `relatively 1flexible material -having- Arelatively large `coefficient -woffriction, Y and meansadjustable to vary thewresistance of# .said face tothe rotation of said-drum.

2. In a shock absorber of the Vcharacterdescribed, a base, a rotatable 'drummounted thereon, a` spiral spring controlling the rotation thereof, a flexible connection member` woundaboutthe-peripheryof said drum-in a direction-opposite to fthat in which said spring tends torotate. said drum,lthemount ing-forsaidl drum on said-basehaving a-face of ielativelyfflexible material having rela-*- tively large -co-eiiicient of friction, 'and a slit wedge-shaped memberadjnst-able Ato vary j the-resistance ofsaid faceto the'rotation of In a shock absorbertation thereof, avflexible connectionmembery wound about the periphery-of said drum-in a directionopposite to that in vwhich saidl of the character: described, abase, a rotatable drum mounted spring tends to rotate saidy drum, the mounting forsaid drum on saidvbase having a face of relati-vely flexible material having relatively large co-'e'liicient of friction, means :adjustable to vary the resistance of said face to the'rotation of said drum, and a` housing carried-by saidlbase and enclosing the latter in said drinn, said adjustablemeans extend ing through said housing. Y

FRANK J. LAHER. 

